The movement of cellular organelles, e. g. chromosomes, vesicles, etc. is of fundamental importance to biology and medicine. Kinesin is one of a group of mechanochemical proteins known to move organelles along microtubules. Until recently only a single archetypal kinesin protein was known. The description of other kinesin-like proteins in A. nidulans, S. cerevisiae and D. melanogaster during the past year has established the kinesins as a family proteins with type-specific functions. The kinesin-like bimC protein of A. nidulans appears to be of special interest because it is required for nuclear division. This grant proposes to continue the structural and functional characterization of bimC with special emphasis on understanding how it works during mitosis. klpA, a second kinesin-like protein of A. nidulans will also be characterized. Molecular genetics will be used to determine the relationship between structure and function of these proteins.